The Achaemenid dynasty

Thirteen kings are counted here, from Cyrus II to Darius III. The reigns are fixed with unusual precision for so remote a period, because the empire's Babylonian subjects dated their contracts and their astronomical records by the regnal years of the reigning king, and enough of those dated tablets survive to anchor the chronology almost year by year; the Greek historians and the later chronographers fill in the narrative.^[1] The boundary years where one reign passes to the next are given below as single years for clarity, though several fell across the turn of the Babylonian year and are cited in the scholarship as, for example, 424/3.

Three of the thirteen barely reigned at all. The man who held the throne in 522 as Cyrus's son Bardiya, whom Darius would brand the impostor magus Gaumāta (see Bardiya and Gaumāta), lasted about six months. In the succession crisis of 424 two half-brothers, Xerxes II and Sogdianus, held power for a few weeks and a few months respectively and were never recognised in Babylonia at all; and Arses, set on the throne by the eunuch Bagoas in 338, was murdered by the same hand two years later. These brief and contested reigns are marked apart in the table and the tree. The list also shows a change in royal naming: from Darius II onward the kings ruled under a throne-name different from the one they were born with, so that a Darius or an Artaxerxes might have begun life as an Ochus or an Arsaces.^[2]

The dynasty is usually called Achaemenid, after Achaemenes; but that name papers over a real division, and a growing body of scholarship prefers to speak of two houses, a Teispid and an Achaemenid, artificially joined.

The evidence is a matter of who claims what. Cyrus the Great, on the Cyrus Cylinder and at Pasargadae, gives his pedigree as son of Cambyses, grandson of Cyrus, descendant of Teispes, all of them kings of Anshan; he calls himself king of Anshan, and he never once names Achaemenes or calls himself an Achaemenid.^[1][3] The eponymous ancestor, and the family name drawn from him, enter the record only with Darius I, and only after his violent accession. In the great inscription at Behistun Darius introduces Achaemenes, declares that for this reason his family is called Achaemenid, and states that eight of his family had been kings before him and that he is the ninth. Yet he never names those eight, and his own father Hystaspes and grandfather Arsames, both alive in 522, had never been kings.^[1][3]

The pedigree Darius offers has him descend from Teispes by a separate branch, parallel to Cyrus's: Teispes, on this account, fathered two lines, the senior running Cyrus I, Cambyses I, Cyrus II, and the junior running Ariaramnes, Arsames, Hystaspes, Darius. The difficulty, pressed hardest by Pierre Briant, is that nothing outside Darius's own claim supports the split. The separate inscriptions in which Ariaramnes and Arsames style themselves Great King are generally judged later fabrications; the theory of two Persian kingdoms descending from one Teispes, Briant concludes, will not stand.^[3] On the reading now shared by most historians, Achaemenes is Darius's invention, or at best his elevation of an obscure name into a founder, and the genealogy binding the two lines is a legitimating fiction: having killed the man who held Cyrus's throne, Darius manufactured a blood-tie to Cyrus and gathered the whole royal house under a single ancestor of his own naming.^[3][4] The same motive is read in the marriages Darius made on his accession, above all to Atossa, a daughter of Cyrus and the mother of his heir: where descent could be asserted, it was also, for safety, married in.^[5]

Not every scholar goes so far. Herodotus preserves, in a speech he gives to Xerxes, a genealogy with two Teispes-figures that is independent of Darius's inscription and does not quite match it, which some take as a trace of a genuine older tradition; and the harmonised, single-family version was the one the dynasty itself believed and propagated. But the direction of the evidence is clear enough that modern reference works increasingly separate the Teispid kings, Cyrus and Cambyses, from the Achaemenids proper, Darius and his successors, and treat the link between them as Darius's work.^[3] It is a rare case in which a dynasty's very name is also its first surviving piece of political fiction.

The tree below draws the royal house as the tradition, once Darius had shaped it, held it to be: a single descent from Achaemenes, forking at Teispes into the line of Cyrus and the line of Darius, and rejoined in the next generation by the marriage of Darius I to Cyrus's daughter Atossa, whose son Xerxes therefore carried both bloods. From Xerxes the succession runs, for the most part directly, down the centre of the tree to the fourth century; the last king, Darius III, was a collateral, descended from Darius II through a younger son, Ostanes, and brought to the throne only when the direct line had been murdered away.

The queens shown are those whose place in the descent is secure and consequential: Cassandane, wife of Cyrus and mother of his sons; Atossa, the hinge of the whole tree; Amestris, wife of Xerxes; Damaspia, whose death on the same day as her husband Artaxerxes I opened the crisis of 424; Parysatis, the formidable mother of Artaxerxes II; and Stateira. Behind these named few stood many more wives and, especially in the later reigns, a great number of sons by secondary unions, from whom the Greek writers spun their tales of harem intrigue; the royal women's real and documented power, economic and administrative rather than dynastic, is treated under Atossa and the Persepolis tablets.

The two centuries fall into three acts. The first is the founding, the work of the Teispid kings: within a single generation Cyrus overthrew the Median king, the Lydian Croesus, and Babylon, and his son Cambyses added Egypt, so that by 522 the largest empire the world had yet seen was in Persian hands and barely twenty years old. The second act opens with the crisis of that year: Cambyses died without a clear heir, the throne was held in the name of his brother Bardiya, and Darius, at the head of six fellow conspirators, killed the sitting king and seized the crown (see the accession of Darius). It was Darius who gave the empire its lasting shape, its satrapies and tribute, its roads and coinage, and Darius and his son Xerxes who carried it to its limits and, in the invasion of Greece, to its first great check.

The third act is the long fourth century, less famous and worse recorded, in which the empire proved far more durable than the Greek picture of decline allows. The century is punctuated by disputed successions, the murderous one of 424 and the war between Artaxerxes II and his brother Cyrus the Younger that ended at Cunaxa in 401, and by revolts of over-mighty satraps; yet the centre held, and Artaxerxes III late in the period recovered Egypt and restored the empire's reach. It was brought down not by rot but by conquest: within six years of Alexander's landing in 334 the last Darius had lost three great battles and his life, murdered in flight by one of his own satraps in 330, and with him the dynasty of Cyrus and Darius came to an end.^[6]